This invention relates to a discrimination apparatus for extracting the maximum-value output from the electric signals being transmitted through a plurality of channel circuits and indexing the relevant channel transmitting the electric signal of the maximum value.
In the field of neuropsychology, for example, studies are conducted to elucidate the mechanism of the nervous system useful for discrimination learning. In one such study, the activities at all the parts of the nervous system are analyzed in accordance with the data obtained by numerous sorts of examinations and numerous experiments are carried out for the elucidation of the functions of the brain in connection with the faculties of language, exercise and memory. In experiments of this nature, necessary information is generally obtained by fastening electrodes at a suitable plurality of positions such as on the brain, the central nervous and the muscles and causing various electric potentials extracted via these electrodes to be delivered as input signals to the learning machine, there to be subjected to proper processing. This technique is applicable not only to such laboratory experiments but also to the control of the operation of artificial arms involving the use of myoelectric potentials (EMG) as instruction signals and to the automatic control of machine tools.
Incidentally concerning the analysis of information in the learning machine, the input unit responsible for the delivery of incoming information to this machine is required to discriminate from among the plurality of electrodes the particular electrode extracting the potential signal of the maximum value and, further, extract the maximum potential of the signal. For this purpose there has heretofore been generally adopted the method which effects the discrimination of the signal of the maximum potential by comparative correlation of the individual signals from the plurality of electrodes and, by means of circuits independently serving the aforementioned plurality of electrodes, accomplishes the indexing of the particular electrode which has extracted the electric potential of the maximum value.
A simple circuit system available for the extraction of the maximum potential is composed in the form of an OR circuit by parallelly connecting a plurality of diodes, for example. This system makes use of the phenomenon that in the particular diode through which the input signal of the maximum potential passes, the maximum potential functions as a reverse bias relative to the remaining diodes. This circuit system, when used alone, is incapable of discriminating from among the diodes the particular diode which has passed the maximum potential. For this circuit system to permit the discrimination effectively, therefore, it is necessary to provide all the diodes respectively with independent circuits specifically adapted for the purpose of discrimination, to furnish the diodes with means capable of performing necessary time-division processing or to incorporate into the system means capable of performing arithmetic operations based on the discriminant functions established in advance. Performance of such complicated processing necessitates use of a fairly complicated circuit system. This inevitable necessity often deprives the technique of its applicability to artificial arms and machine tools.
An object of this invention, therefore, is to provide a discrimination apparatus of simple circuit configuration, which apparatus extracts the maximum potential from the input signals being transmitted through a circuit incorporating a plurality of input channels and, at the same time, indexes the channel in which the aforementioned maximum potential has been extracted.